Paper closure member for paper containers



:azzlazzaz w. E. AMBERG PAPER CLOSURE man FOR PAPER couumnns Filed Sept.24, 1948 Sept. 25, 1951 Z; M 5. W49 fly/flm pm;

Patented Sept. 25, 1951 PAPER CLOSURE MEMBER FOR- PAPER CONTAINERSWalter E. Amber'g, Beverly Shores, Ind., assignor to Lily-Tulip CupCorporation, Chicago, 111., a corporation of Delaware ApplicationSeptember 24, 1948, Serial No. 51,043

2 Claims. (01. 229-43) This invention is directed to paper closuremembers for paper containers. The subject matter disclosed but notclaimed herein is disclosed and claimed in my co-pending divisionalapplications Serial No. 120,965 and Serial No. 120,966, filed October12, 1949.

Heretofore, various types of paper closure members for paper containershave been proposed and utilized but they have all, for various reasons,failed to produce satisfactory results. Openended paper containers to beclosed by paper closure members are usually provided with an externalrim at the open end thereof and an internal groove adjacent thereto.members for such paper containers have been generally of three types, a.stiff paper disc adapted to fit in the internal groove of the papercontainer, or a paper cover having a flange frictionally received in theopen end of the paper container and overlying the rim thereof, or apaper cover having a depending flange adapted to snap over the externalrim of the paper container.

In the first type of paper closure member, the stiff paper disc isdiflicult to insert into'the annular groove of the paper container.Extreme care in application is required for any tilting of the paperdisc or any application of uneven pressure usually results in plungingthe paper disc into the contents of the paper container with consequentspilling and contamination of the contents. The fit of the paper disc inthe annular groove is also critical for, if the fit is too tight. thepaper disc is too difficult to apply, and if the fit is too looseleakage will occur. Extremely close tolerances must be maintained andthis is diflicult and expensive to do with formed paper. After the paperdiscs are applied they are extremely difiicult to remove and in thisconnection it is necessary to provide removing tabs of the like to thepaper discs to assist in removing the same from the paper container.Quite often these removing devices tear off from the paper discs duringthe removing operation. Further, the rims of the paper containers arenot protected by the paper discs and they become dirty and contaminatedand result in contamination of the contents when poured from the papercontainer. Some of the foregoing difliculties encountered with the useof the stiff paper discs are overcome by the use of the second type ofpaper closure member, but here other difficulties are encountered. Sincethe paper cover having a flange received in the open end of the papercontainer and overlying the rim thereof is merely frictionally held inplace on the container, it may be Paper closure readily dislodgedcausing spilling of the contents of the container. Substantially anyupward force applied to the flange, as during handling or packing thecontainers, will operate to dislodge the cover. It has been-found thatthe use of friction v alone for retaining the paper cover in place onthe paper container is wholly inadequate. Here, also, tolerances arequite critical for if the fit is too loose leakage is bound to occur.

As a result of the foregoing difficulties, great efforts have been madetoward the third type of closure member, but here again inherentdi'fliculties have been encountered. The paper cover having a dependingflange adapted to snap over the external rim of the paper containermust, of necessity, project beyond and below the rim of the papercontainer. This requires extra space for the packing of the closedcontainers and also requires extreme care in handling and packing. Ifthe projecting edge of the depending flange of the paper closure memberis severely bumped or is hung up on the top of an adjacent containerduring packing, the closure member is almost invariably dislodgedresulting in spilling and contamination of the contents of thecontainer. Here, also, the tolerances are quite critical for, if the fitbetween the closure member and the container is too tight, theapplication and removal of the closure member becomes diflicult and, iftoo loose, leakage will occur. Since thegripping action of the closuremember takes place at the extremity thereof, it may be readilydiminished by rough handling.

The principal object of this invention is to provide an improvedpaperclosure member for a paper container wherein the difficultiesencountered by the foregoing paper closure members are eliminated,wherein the paper closure member may be easily applied to and removedfrom the paper container, wherein the paper closure member is securelyheld in place on the paper container, wherein the paper closure membercannot be dislodged during handling or packing, wherein critical fittolerances are not required, wherein leakage between the paper closuremember and the paper container is eliminated, and wherein the rim of thepaper container is protected from dirt and contamination.

The paper closure of this invention is adapted for use with a papercontainer having an external rim at the open end thereof and an internalgroove adjacent thereto, the closure being made from a single sheet ofpaperboard, and includin a closure end wall portion and an integral sideflange portion extending upwardly therefrom throughout the peripherythereof. The juncture of the end wall portion and the side flangeportion consists of a compressed solid peripheral bead in substantialplanar alignment with the periphery of the end wall portion andextending beyondthe upwardly extending flange portion to form areinforced peripheral extension of the end wall portion. The side flangeportion lies adjacent the open end of the paper container and thecompressed solid peripheral bead, forming an extension of the end wallportion, snaps into the internal groove of the paper container and isheld flrmly therein. Thus, the paper closure member is positivelyretained in the paper container by the compressed solid peripheral bead.

Preferably, the upper edge of the side flange portion is formedoutwardly into an external reentrant flange portion to overlie the rimof the paper container to protect the same from dirt and contamination.The side flange portion also operates to prevent plunging of the paperclosure member into the contents of the paper container duringapplication of the closure member and provides a strong and readilyaccessible means for removing the closure member from the papercontainer. Any application of force to the external reentrant flangeportion of the paper closure member during handling or packing will not.dislodge the closure member for it is flrmly held in place by theexternal compressed peripheral bead engaging in the internal groove.Because of the seal formed by the side flange and external head of thepaper closure member leakage of the contents of the paper container iseflectively prevented and close-fit tolerances are not required.

A further object of this invention resides in the cooperativerelationship between the paper container and the paper closure member ofthis invention.

Other objects and advantages will become apparent to those skilled inthe art upon reference to the accompanyin specification, claims, anddrawing, in which Figure l is a side elevational view of a papercontainer with the paper closure member of this invention appliedthereto.

Fig. 2 is an enlarged partial sectional view taken substantially alongthe line 2-2 of Fig. 1 illustrating the cooperative relationship betweenthe paper container and the paper closure member.

Fig. 3 is a cross-sectional view showing suitable apparatus, withcertain portions broken away, for forming the paper closure member withthe parts in a position at the start of the forming cycle.

Fig. 4 is a view similar to Fig. 3 but showing the parts midway in thecycle of operation.

Fig. 5 is a view similar to Figs. 3 and 4 but showing the parts at thecompletion of the cycle of operation.

Referring first to Figs. 1 and 2 the paper container is generallydesignated at It and includes a side wall H which may be frustro-conicalin contour for stacking purposes and provided at its bottom l2 with abottom wall. The upper open end of the paper container is provided withan external rim l3 and adjacent the upper open end of the papercontainer it is indented outwardly at H to form an internal groove IS.

The paper closure member of this invention is generally designated at Hand it includes a closure end wall portion I8 and an upwardly extendingside flange portion [9. The upper edge of the side flange portion I 9 isprovided with an external reentrant flange portion 20. The ,Iuncture ofthe closure end wall portion i8 and side flange portion I9 is deformedoutwardly to form an external compressed solid peripheral bead 2! at thejuncture. the bead being in substantial planar alignment with theperiphery of the end wall portion l8 and extending beyond the sideflange portion IS.

The paper closure member I! is adapted to be received in the open end ofthe paper container III. The external bead 2|, forming a reinforcedextension of the closure end wall portion I8, is received in the annulargroove l5 oi the paper container and the side flange portion ll mayfrictionally engage the side wall ll of the paper container adjacent itsopen end. The external reentrant flange portion 20 overlies the rim IIto protect the same from dirt and contamination.

To apply the paper closure member to the paper container all that isnecessary is to insert it in the open end of the paper container,whereupon the external compressed peripheral bead 2l snaps into andengages in the internalgroove l5 and the side flange portion mayfrictionally engage the side wall of the paper container. The sideflange portion l9 and the external reentrant flange portion 20 operateduring application of the closure member to prevent plunging of the sameinto the contents of the paper container. Because the externalcompressed peripheral bead 2| is a continuation. of the closure end wallportion It it is firmly held in engagement with the internal groove l5.This firm engagement, especially whentaken in conjunction with thetriotional engagement of the side flange portion It, prevents the paperclosure member from being dislodged during handling or packing, alsoprovides an eifective seal between the paper closure member and thepaper container and eliminates the necessity for extremely close-fittolerances as heretofore required.

In order to remove the paper closure member from the paper container,all that is necessary is to uncurl a portion of, the external reentrantflange portion 20 so that it may be firmly grasped to pull the closuremember from the container. Upon such pulling the external compressedperipheral bead 2| of the paper closure member is snapped vout of theinternal groove I 5.

Referring more particularly to Figs. 3-5: apparatus suitable for makingthe paper closure of this invention includes a female die 25 having abottom wall member 2! which is movable between a. retracted positionillustrated in Figs. 3 and 4 and an advance position illustrated in Fig.5; a male die 30 movable relative to said female die from a retractedposition illustrated in Fig. 3 to an advance position illustrated inFig. 4; and a die ring 3| surrounding said male die 30 and movable withthe relative thereto. The female die 25 is undercut or recessed at 26 toprovide an opening into which the bottom member 21 is slidably disposedand to provide a lip 29 defining a smaller opening for receiving themale die 30. The male die 30 and female die 25 being of complementaryshape and of such relative dimensions as to provide, between the maledie 30 and lip 29 on female die 25, a peripheral space approximatelyequal in width to the thickness of the paperboard 'to be operated upon(said thickness hereinafter being referred to as paperboard thickness)and so as to provide between the plunger 30 and peripheral wall ofrecess 20 a peripheral space whose width is substantially greater thanone paperboard thickness and preferably less than two paperboardthicknesses.

The female die 25 is preferably provided with an upwardly extendingshoulder 28 constitutin a male rim die cooperatively disposed withrespect to a complementary groove, provided in the rin 3|, constitutinga female rim die which surrounds the male die 30. The ring 3| is movablefrom a retracted position as illustrated in Fig. 3 to an advanceposition as illustrated in Figs. 4 and 5 an together with thecomplementary portion 28 of die 25 provides die means for forming theclosure rim and serves for clamping the partially formed article duringthe latter part of the cycle of operations.

Fig. 3 illustrates the parts of the machine at the start of the formingcycle. A paper board blank IIA, circular in configuration for formingthe paper closure member I1, is inserted on the top of the female die asillustrated in Fig. 3. The male die is then advanced to carry the paperblank with it into engagement with the movable bottom wall 21 of thefemale die when the bottom wall is in its retracted position- Thisoperation forms the paper board blank into a closure end wall portion l8and a side flange portion IS.

The die ring 3| is then advanced and cooperates with the male rim die 28to form the external reentrant flange portion 20 on the upper edge ofthe side flange portion l9. At the end of these operations the machineparts take positions illustrated in Fig. 4 wherein the paper blank isformed into a closure end wall portion ill, a. side flange portion l9,and an external reentrant flange portion 29.

After the parts are in the position illustrated in Fig. 4 the movablebottom wall 21 is advanced simultaneously with retraction of the maledie 30 to the positions illustrated in Fig. 5. This simultaneousmovement of the movable wall 21 and the male die 30 operates to deformthe juncture of the closure end wall portion and side flange portion ofthe paper closure member outwardly into the annular recess 26 to formthe relatively rigid external peripheral bead 2 I. The simultaneousmovement of the bottom wall I! and the male die 30 is such as tocompress the deformed external peripheral bead 2| so that it becomes arelatively rigid external bead which permanently holds its shape.

To remove the formed paper closure member from the machine the bottomwall 21 of the female die, the male die 30, and the female rim die 3|are retracted and a plunger 32 is moved upwardly against the center ofthe closure wall [8 to snap the paper closure member from the annularrecess 26. The parts are then in the position to repeat the cycle ofoperation. If desired, the female die 25 may be radially severed into aplurality of segments and they may be moved outwardly for the purpose ofclearing the external peripheral bead 2! of the paper closure member toprovide for ready removal of the paper closure member from the machinein the event that snap removal is not desired.

Thus, the method of forming the paper closure member includes forming apaperboard blank into a closure end wall portion and side flangeportion, forming the edge of the side flange portion into an externalreentrant flange portion, and outwardly deforming the juncture of theclosure wall and side flange into a compressed solid peripheral externalbead.

While for purposes of illustration one form of this invention has beendisclosed, other forms thereof may become apparent to those skilled inthe art upon reference to this disclosure and therefore this inventionisto be limited only by the scope of the appended claims.

I claim as my invention:

1. A paper closure member, adapted for use with a paper container havingan internal groove adjacent the open end thereof, comprising a singlesheet of paper board formed into a closure end wall portion and anintegral side flange portion extending upwardly therefrom throughout theperiphery thereof, the juncture of said portions consistin of acompressed solid peripheral bead in substantial planar alignment withthe periphery of the end wall portion and extending beyond the upwardlyextending flange portion to form a reinforced peripheral extension ofthe end wall portion for engagement in the internal groove of the papercontainer.

2. A paper closure member adapted for use with a paper container havingan external rim at the open end therof and an internal groove adjacentthereto, comprising a single sheet of paper board formed into an endwall portion and an integral side flange portion extending upwardlytherefrom throughout the periphery thereof, the juncture of saidportions consisting of a compressed solid peripheral bead in substantialplanar alignment with the periphery of the end wall portion andextending beyond the upwardly extending flange portion to form areinforced peripheral extension of the end wall portion for engagementin the internal groove of the paper container, and said upwardlyextending side flange portion having an external reentrant portion forreceiving the external rim of the paper container.

WALTER E. AMBERG.

REFERENCES CITED The following references are of record in the flle ofthis patent:

UNITED STATES PATENTS France Feb. 4, 1935

